Hagia Sophia Interior Mosaic, Istanbul, Turkey — Byzantine craftsmen covered Hagia Sophia's upper galleries with gold-ground mosaics depicting Christ, the Virgin, and emperors. The great Deesis mosaic in the upper south gallery, showing Christ flanked by the Virgin and John the Baptist, is considered one of the masterpieces of Byzantine art.
© Osama Shukir Muhammed Amin FRCP(Glasg), CC BY-SA 4.0, via Wikimedia Commons